1. Field
Example embodiments relate to structures for measuring misalignment of patterns and methods of measuring misalignment of patterns using the same. Example embodiments also relate to structures for measuring misalignment of conductive patterns in a semiconductor device and methods of measuring misalignment of conductive patterns in a semiconductor device using the same.
2. Description of the Related Art
After performing processes for forming semiconductor devices on a wafer, misalignment of patterns of the semiconductor devices may be measured. However, the wafer may be damaged during the misalignment measurement. As a result, the measurement may be performed on a monitor substrate or a test substrate (as opposed to the actual wafer). Processes substantially the same as those performed on the actual wafer may be performed on the test substrate, and misalignment of patterns, (e.g., test element group (TEG)) on the test substrate may be measured. Misalignment of patterns in a semiconductor device manufacture process may increase a design rule of semiconductor devices. As a result, the chip size including the semiconductor devices may increase, and the stability of the process may be deteriorated.
Light or resistance may be used for measuring misalignment of patterns. When light is used for measuring misalignment of patterns, a reflective light from the patterns may be detected, and the detected reflective light may be transformed into an electrical signal by a photodiode or a charge coupled device (CCD). However, the real misalignment may be different from the calculated misalignment by the electrical signal.
When the resistance is used for measuring misalignment of patterns, a current may be applied to the patterns, and a change of resistance may be detected. The resistance may be detected by a current flowing through upper and lower patterns, which are connected to each other at a specific contact area. When the contact area becomes smaller from misalignment, the resistance may increase (and vice versa). However, the patterns may be electrically connected to each other. As a result, even if the upper and lower patterns are misaligned in a specific direction (such that some contact areas become smaller while other contact areas become larger), a change in resistance may still not occur. Thus, the misalignment may not be detected.